Process of fractioning bromin apart from chlorin



No. 752,286. PATENTEDFEB. 16, 1904.

H. H. DOW.

PROCESS OF FRAGTIONING BROMIN APART PROM GHLOEIN.

APIILIOATI'ION FILED- 11M. 16, 1903.

v I0 110mm.

Q M, I Tim land, county of Midland, and State of Michigan,

UNITED STATES Patented February is, 1904.

PATENT OFFICE,

CHEMICAL COMPANY,

OF MICHIGAN.

OF MIDLAND, MICHIGAN, A CORPORATION I PROCESS OF FRACTIONING BROMlN APART FROM CHLORIN.

SPECIFICATION forming part of Letters Patent No. 752,286; dated Iliebruary 16, 1904.

' sp nasoi min September 16, 1903. Serial No. 173,363. (Nospceimena) To alZ whom it rrta-y concern: Y

Beit known that I, HERBERT H. Dow, a citizen of the United States, and a resident of Midhave invented a new and useful Improvement in Processes of Fractioning Bromin Apart from Chlorin, of which the following is a specification, the principle of the invention being herein explained'and the best mode ill-WhiCh I have contemplated applying that principle, so as to distinguish it from other inventions.

My invention consists of an improved process for fractioning bromin apart from chlorm, andv thus obtaining a mixture of bromin and chlorin in which the proportion of bromin to chlorin may be any that is desired up to a practical limit, the production of a mixture in which the amount of chlorin shall be small in comparison with the amount of bromin being especially sought. Said process consists of a series of steps hereinafter fully described.

The annexed drawing and the following description set forth in detail one mode of carrying out the invention, such'disclosed means constituting but one of various ways in which the principle of the invention maybe used.

In said annexed drawing is represented a diagrammatic view of a form of apparatu used in my improved process.

and chlorin which are obtained by the oxidation of natural brines in that heretofore this separation has been accomplished by chemical processes and depended upon the fact that chlorin will liberate bromin from bromids, while in this process the method is purely mechanical and depends upon the fact that the bromin in a brine solution is more volatile than the chlorin formed in the solution at the Ihave found that when a natural the brominthns set free the first portions of air escaping from the bromin solution willcarry the purest bromin and later portions of air will carry a very -impure bromin, the impurity in both cases being chlorin or a volatile compound of chlorin or a combination of the My improved process is a radical departure in the methods of fiacuionin'g apart bromintwo, some or all of which are produced in quite a large quantity when the brine is oxidized.

Although the method of fractioningbromin the methods heretofore used and, especially from that described and claimed in my United States Letters Patent No. 714,160, the apparatus' used in this'process is nearly identical with that used in said Letters Patent, differing only in these respects: auxiliary oxidizer M and its connections,and the connection through the blower F between the absorption-towers L and the blow-out towers C, which are shown and described in the View accompanying the patented process are omitted in this. improvement. There is an air-inlet 0' provided for not provided in thepatented process. Also in this process the connection 0' leads from N instead of from the towers C to the auxiliary oxidizer M. The rest of the apparatus both in the main and auxiliary systems performs the same functions in this process as those disclosed in the patent, and Ishall therefore describe neither them nor their functions lnioll'le in detail, the lettering being identical in ct K My improved process is carried on as follows: Raw brine from the reservoir R is first allowed to pass through-the'absorber Q, where it takes up more or less bromin' and chlorin, and passes on to the reserviorA through the connection 0.. From here it passes through duct 1) to the oxidizer B, where by any of the means explained in my reissued Letters Pat/ ent No. 11,232 it is oxidized with the formation of free bromin, more or less chlorin incidentally and of necessity being simultaneously set free. From the oxidizer the brine carrying all the dissolved bromin in the free state passes through duct '0 to theblow out allowed to enter through the inlet a, anda part of the bromin which is the purest is carried with a relatively small amount of chlorin into the purifiers E through the pipe G, thence apart from chlorin is a radical departure from the blow-out towers C to the blow-out towers the blow-out'tower C in this process that is a towers C. Here a limited amount-of air is a through the pipe H, purifiers J, in which a strong bromid solution (provided from a suitable source, such as the receptacle X) is caused L, which may contain any suitable material,

such as sodium carbonate, (the latter being provided from a suitable source of supply, such as the receptacle Y,) which will combine with the bromin exactly as described in Letters Patent No. 714,160. As has been mentioned above, the bromin in a brine solution is more volatile than the chlorin in thesolution formed at the same time, and by this blowing of the brine with a limited amount of air a mixture of bromin and chlorin is obtained in which the proportion of bromin to chlorinv is much higher than the average proportion of the solution and a far purer bromin product obtained than when a large. amount of air is used or when limited amounts of air are used successively. The proportion of bromin carried away to. the air used also increases with the decrease in the amount of air used. The brine in the towers C still contains a large amount of free halogens, and from it considerable quantities of a less pure bromin may be obtained. The brine is hence conducted through the pipe 0 to the blow-out towers N, where it is brought into contact with a large amount of air and all thedissolved free halogens blown out, whence they are carried through the duct 0 to the absorption-towers Q and are taken up by and serve to oxidize the fresh brine coming down from the reservoir R into the towers Q, through duct q. During the passage of the different solutions through the various parts of the apparatus pumps 47., g, e, j, Z, and a at the'bases ofthe systems of towers N, Q, E, J, L, and .C, respectively, serve to convey the various solutions contained or flowing through said systems of towers successively to the one, two, three, or any numbers of towers comprising each of the respect1ve systems. i

I shall call a series of blow-out towers, such as C and N, hereinafter an air system, meaning thereby a tower or plurality of towers connected together for blowing out by means of air a part of the bromin.

'As the exact control of the amount of oxidation that takes place is very important in order to get a maximum yield'of bromin of the greatest purity consistent with a high extraction, it has become very important that this part of the process should be simplified. It is for this reason that in theimproved proc e'ss herewith described I have dispensed with one of the two oxidizers used in my process as described in Letters Patent No. 714,160. The process is, further simplified by reason of the fact that a slight excess of oxidation in the process herein described is not as detrimental to the final product as would be in case my patented process was employed.

The large amount of bromin blown out in the air system C compared with the amount of air used makes it possible to more completely remove the chlorin in a limited number of purifying-towers than where the bromin is highly diluted with air and yet leave the bromin sufficiently pure for the production of commercial bromids.

It will be noticed that'by controlling the amount of air allowed to enter the air system C bromin of any desired purity up to the practical limit of purity may be obtained and that the proportion of bromin to chlorin in the mixture thus blown out may be as large or small as desired, and, furthermore, bromin may be recovered in any desirable quantity in the said air system C, the remainder, an

amount as great as is desired, being allowed to be carried by the brine to the second air system N.

' Other modes of. applying the principle of v my invention may be employed instead of the one explained, change being made as regards the step or steps herein disclosed, provided the means stated by any one of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention- 1. The steps in the process of fractioning bromin apart from chlorin which consist, in oxidizing bromid-containing brine, in blowing out the purest bromin thus set free by a limited amount of air, then blowing out the remainder of the bromin without further oxidation by a large amount of air, and recovering both portions of bromin thus blown .out

by suitable absorbents. Y a

2. The steps in the process of fractioning bromin apart from chlorin which consist, in oxidizing bromid-containing brine, in blowing out the purest bromin thus set free by a limited amount of air,.recovering the same by means of sodium carbonate, blowing out the remainder of the bromin without further oxidation by a large amount of air, and then recovering this'bromin by means of absorbing it in a natural brine.

Signed by me this 11th day of September, 1903.

HERBERT H. now.

Attest: v

D- W. CHASE, FLORA M. THoMPsoN. 

